A logo is a graphic symbol that provides a non-verbal expression of the conceptual/marketing message communicated by a given company, becoming identified with it. The large logo bank created by Emanuel Cahana is the product of manual work processes that have become all but obsolete. The sketches and drawings of letters and forms were typically created using a technical pen (a thin pen that can be adjusted to create lines of varying widths).  In many cases, the commissioner of the logo was presented with several choices. Cahana played with forms and letters, creating a complex graphic language that enacts a dialogue between changing and recurrent patterns, as well as an interplay between lines and colors, letters and forms.